1 8 Master Minds of Modern Science 



new valve provided a means of amplifying the most 

 minute currents of electricity to almost any extent. But 

 once more disappointment was ahead. It was found 

 that for successful television an amplification at least a 

 thousand times greater than that obtained by Sir John 

 Fleming's valve would be required. 



It will be seen, therefore, that the real stumbling-block 

 to the successful production of wireless sight for fifty 

 years was the discovery of a light-sensitive device speedy 

 enough, and sensitive enough, to permit the transmission 

 not of vague shadows, but of clear, sharp, complete pic- 

 tures, at the speed of twelve or more per second. 



In other countries — in the United States, France, and 

 Germany — patient investigators were at work on these 

 problems, but between the discovery of the light-sensitive 

 properties of selenium in 1873 and Baird's first successful 

 experiment in the transmission of shadows in 1925 there 

 stretch fifty years of heart-breaking disappointments — 

 fifty years during which apparently no progress was made. 

 This period, however, was really that of a strenuous 

 international race for the honour of achieving television, 

 and the prize was won by a Scottish engineer who fought 

 ill-health, discouragement, and lack of funds, to experience 

 at last the thrill of watching, not a vague shadow, but a 

 face having expression, with light and shade, all this being 

 conjured by the inventive genius from the apparatus to 

 the creation of which he had so tirelessly devoted himself. 



John Logie Baird is the son of a Scottish Presbyterian 

 minister, and was born at Helensburgh. While still a 

 schoolboy he showed signs of the inventive instinct which 

 was later to dominate his life. It was then that he set up 

 a model telephone exchange by his bedside to connect 

 him with four friends living near by. The telephones 

 were precariously connected by wires hanging across the 

 village street, and it was this fact that brought John 

 Baird's first effort at construction to an untimely end, for 



